Numerical study of a dual-polarized Focal Plane Array (FPA) with Vivaldi elements placed in the vicinity of a large feed box using the parallelized FDTD code GEMS

Dense Focal Plane Arrays (FPAs) are currently regarded as one of the strongest candidates for use in next generation radio telescopes, such as the Square Kilometer Array (SKA). Since neither the conventional waveguides nor horn arrays are able to realize the full potential of the SKA, the Vivaldi array, comprising of electrically small wideband tapered slot antennas, has been designed to fill this need. An initial version of the 144 elements dual-polarized Vivaldi element array, whose design is based on the use of the dense FPA concept, has been realized at ASTRON and has been successfully tested on the Westerbork Synthesis Radio Telescope (WSRT) [1], [2]. The tests have demonstrated that it is feasible to build a wideband FPA with illumination efficiency superior to that of a conventional waveguide/horn.